Shock proof buckle for safety belts

Abstract

A buckle for a safety belt, especially for motor vehicles, for receiving and locking an insertion tongue. A locking latch is provided that is biased in an opening direction and is pivotably mounted in a buckle housing such that in a locking position the locking latch extends into a recess of the insertion tongue. A locking bar is movably mounted in the housing at an angle to an insertion path of the insertion tongue, with the locking bar securing the locking latch in the locking position thereof. A sliding key is guided transverse to a plane of movement of the locking latch for cancelling the locking position thereof via actuation of the locking bar. To protect the buckle from shock, a compensating mass is mounted in the housing such that it is movable relative to the locking bar. The compensating mass serves for fixing the locking bar in position. During acceleration in the same direction as a pushing-in direction of the sliding key, the compensating mass directly supports the locking bar and fixes the position thereof. A spring is supported on the buckle for spring-loading the compensating mass toward a position that fixes the locking bar.

We claim: 
     
       1. A buckle for a safety belt, especially for motor vehicles, for receiving and locking an insertion tongue, comprising: a housing having an insertion passage for said insertion tongue;   spring-loaded ejector means disposed in said insertion passage of said housing;   a locking latch that is biased in an opening direction and is pivotably mounted in said housing such that in a locking position said locking latch extends into a recess of said insertion tongue;   a locking bar movably mounted in said housing at an angle to an insertion path of said insertion tongue, with said locking bar securing said locking latch in said locking position thereof;   a sliding key that is guided transverse to a plane of movement of said locking latch for cancelling said locking position thereof via actuation of said locking bar;   to protect said buckle from shock, compensating mass means mounted in said housing such that said compensating mass means is movable relative to said locking bar, said compensating mass means serving for fixing said locking bar in position, wherein during acceleration in the same direction as a pushing-in direction of said sliding key, said compensating mass means directly supports said locking bar and fixes the position thereof; and   spring means supported on said buckle for spring-loading said compensating mass means toward a position that fixes said locking bar.   
     
     
       2. A safety belt buckle according to claim 1, in which said compensating mass means, and an actuating projection of said sliding key, are respectively disposed in the same plane relative to a pivot axis of said locking bar and accommodate said locking bar between them. 
     
     
       3. A safety belt buckle according to claim 2, in which said compensating mass means is longitudinally displaceably guided in said housing and upon actuation of said locking bar via said sliding key yields to the movement of said locking bar. 
     
     
       4. A safety belt buckle according to claim 1, in which said compensating mass means is in the form of a pivot lever that extends over a path of movement for said sliding key in a bow-shaped manner, with said pivot lever being pivotably mounted in said housing against the force of said spring means, which holds said pivot lever in the position where it fixes said locking bar. 
     
     
       5. A safety belt buckle according to claim 4, in which said pivot lever is provided with a stop member that cooperates with said locking bar and that, on a side of said locking bar facing said sliding key, acts upon an end of said locking bar that secures said locking latch. 
     
     
       6. A safety belt buckle according to claim 4, in which said pivot lever has a pivot axis that is disposed between the planes of movement of said sliding key on the one hand and a locking surface of said locking bar on the other hand. 
     
     
       7. A safety belt buckle according to claim 5, in which said pivot lever, which forms said compensating mass means, is provided with a second stop member for fixing the position of said sliding key in the event of acceleration acting counter to said pushing-in direction of said sliding key. 
     
     
       8. A safety belt buckle according to claim 7, in which said stop members of said pivot lever, relative to a vertical plane of movement of said sliding key, are respectively disposed on opposite sides of said pivot lever. 
     
     
       9. A safety belt buckle according to claim 7, in which said housing is provided with a support means to limit the pivot movement of said pivot lever. 
     
     
       10. A safety belt buckle according to claim 7, in which said pivot lever has an essentially S-shaped configuration including an upper portion and a lower portion, with said first-mentioned stop member for said locking bar being disposed at an outer end of said lower portion of said S-shaped configuration, and said second stop member for said sliding key being disposed at a bend of said lower portion of said S-shaped configuration, and with said upper portion of said S-shaped configuration having a bend that provides freedom of movement for said sliding key during opening of said buckle. 
     
     
       11. A safety belt buckle according to claim 1, in which, during unlocking of said buckle, an actuating projection of said sliding key passes through an idle stroke prior to engagement against said locking bar. 
     
     
       12. A safety belt buckle according to claim 1, in which, to protect said buckle from shock in the event of acceleration acting counter to said pushing-in direction of said sliding key, a second compensating mass means is longitudinally displaceably guided in said housing and holds said locking bar in its position where it secures said locking latch. 
     
     
       13. A safety belt buckle according to claim 12, in which said second compensating mass means acts on an end of said locking bar remote from an end thereof that serves for engagement with said sliding key, with said second compensating mass means being provided with a hook-shaped formation that extends over said locking bar to hold same in its position where it secures said locking latch. 
     
     
       14. A safety belt buckle according to claim 12, which includes means for connecting said second compensating mass means and said locking bar with play. 
     
     
       15. A safety belt buckle according to claim 1, in which said spring means for spring-loading said compensating mass means is supported on said housing. 
     
     
       16. A safety belt buckle according to claim 1, in which said spring means for spring-loading said compensating mass means is supported on a projection of said locking latch.